Flower Glossary: Thistle

Thistles sometimes get a bad rap because of their prickly exterior. They’re no fun to wander into unexpectedly, but if you work with them carefully they can add such beauty and sculptural form to an arrangement (they dry well, too!). The most common variety that I see in floral shops around my area are these stunning Blue ‘Super Nova’ Thistles like the one above. They have such a rich blue-purple color and are so striking they barely need any accompaniment in a vase. There are hundreds of varieties of thistles, but today I’m focusing on the basics, from their use in medicine and their importance to Scotland to their status as Eeyore’s most beloved snack. xo, grace

Additional Information about the Thistle:

Full Name: Cynareae are a tribe of plants including thistles, which are part of the broader Asteraceae (Daisy) family.

Growing details: Often regarded as a weed, the thistle grows quickly and easily in warm sunny areas. Because its growing style is so invasive, not much work is needed to expand flower beds once the initial plants start growing.

Varieties: There are hundreds of varieties of thistles, including stunning varities like the Blue ‘Super Nova’ Thistle shown above. However, the Audobon Society North American Field Guide to Flowers lists three major species in North America: the Canada, bull and yellow thistles. The Milk Thistle is particularly useful for its healing purposes.

Size: Thistle plants can grow up to 3.5 feet tall and their heads can be 1.5 to 4 inches in diameter.

Cost: Thistles sell, on average, for around $2-$3 per head.

Interesting facts: The thistle has healing properties. It’s sap is helpful for a variety of liver problems. (Also, Eeyore’s favorite food in Winnie the Pooh is thistle!)

Actually, I’m no plantswoman but I’m pretty sure this is a photo of an Eryngium, most commonly known as sea holly (occasionally called alpine thistle, colloquially). Also, it looks more like ‘Jackpot Blue’ Eryngium than ‘Super Nova’.

It’s invasive nature also makes it… incredibly invasive! West of the Mississippi anyway, you can ruin a farmer by planting thistle and letting it invade his or her hay crop (since he won’t be able to sell the product including “noxious weed material” to avoid spreading it (its even illegal in some western states to spread or allow several varieties of thistles to grow on your property). Even the native thistles are a problem for agriculture. They’re beautiful, but please be very very careful actually planting these outside if you live in the US!

I am a conservation botanist and yes, I too will say that the photo is of Eryngium, from the Apiaceae family, while plants most commonly called “thistle” are from several genera in the Asteraceae. Common names can lead to confusion. The text sometimes refers to the Asteraceae sense of thistle, and sometimes to the Eryngium “thistles”.
The Asteraceae thistles include species that are invasive in North America and crowd out diversity but there also are Asteraceae thistles which are very rare, such as Cirsium pitcheri. The Asteraceae thistles support a diversity of insects, which is great in itself, great for pollination and great food for birds. Thistle seeds too are eaten by wildlife.
I’ll stop there with my praise for thistles. I enjoy seeing the floral trade plants featured on D*S. Just hoping to help get correct information out there.

Love the beautiful photo of this thistle/eryngium! (I agree with Alexa that it does look more like “Jackpot” than “Supernova”). Had to jump in to comment that the nomenclature is really just a matter of what is used as a common/trade name vs. botanical name. It’s not too dissimilar to what’s happened with amaryllis (common name) vs. hippeastrum (botanical name). Many florists and flower wholesalers will call eryngium a thistle. It’s the common term that while not botanically correct has become commonly used and recognized for eryngium, so it’s no surprise that Grace’s florist called it by that name. Frankly, I think it’s a lot easier to say! Keep up the great content Design Sponge team!

I love these! Reminds me of an Eryngium I’d love to grow – Mrs. Wilmott’s Ghost (erynginum giganteum) with a great story behind the name – Mrs Wilmott (aka eccentric English gardening heiress) who fired help at the sight of a single weed and surreptitiously flung seeds of these large plants wherever she saw fit.

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